Dates and Time

Arrays of date and time values that can be displayed in different formats

The date and time data typesdatetime,duration, andcalendarDurationsupport efficient computations, comparisons, and formatted display of dates and times. Work with these arrays in the same way that you work with numeric arrays. You can add, subtract, sort, compare, concatenate, and plot date and time values. You also can represent dates and times as numeric arrays or as text. For more information, seeRepresent Dates and Times in MATLABor watchDate and Time Arrays.

Functions

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Create Date and Time Arrays

Create datetime Arrays

`datetime`	Arrays that represent points in time
`NaT`	Not-a-Time

Create duration Arrays

`一年s`	Duration in years
`days`	Duration in days
`hours`	Duration in hours
`minutes`	Duration in minutes
`seconds`	Duration in seconds
`milliseconds`	Duration in milliseconds
`duration`	Lengths of time in fixed-length units

Create calendarDuration Arrays

`calyears`	Calendar duration in years
`calquarters`	Calendar duration in quarters
`calmonths`	Calendar duration in months
`calweeks`	Calendar duration in weeks
`caldays`	Calendar duration in days
`calendarDuration`	Lengths of time in variable-length calendar units

Split Dates and Times

Extract Components by Time Unit

`一年`	Year number
`quarter`	Quarter number
`month`	Month number and name
`week`	Week number
`day`	Day number or name
`hour`	Hour number
`minute`	Minute number
`second`	Second number

Split into Numeric Arrays

`ymd`	Year, month, and day numbers of datetime
`hms`	Hour, minute, and second numbers of datetime or duration
`split`	Split calendar duration into numeric and duration units
`time`	Convert time of calendar duration to duration
`timeofday`	Elapsed time since midnight for datetimes

Determine Type, Time Zone Offset

`isdatetime`	Determine if input is datetime array
`isduration`	Determine if input is duration array
`iscalendarduration`	Determine if input is calendar duration array
`isnat`	Determine NaT (Not-a-Time) elements
`isdst`	Determine daylight saving time elements
`isweekend`	Determine weekend elements
`timezones`	List time zones
`tzoffset`	Time zone offset from UTC

Shift or Calculate Differences Between Dates

`between`	Calendar math differences
`caldiff`	Calendar math successive differences
`dateshift`	Shift date or generate sequence of dates and time
`isbetween`	Determine elements within date and time interval

Convert to Numbers and Strings

Convert to Numbers

`datenum`	Convert date and time to serial date number
`datevec`	Convert date and time to vector of components
`exceltime`	Convert MATLAB datetime to Excel date number
`juliandate`	Convert MATLAB datetime to Julian date
`posixtime`	Convert MATLAB datetime to POSIX time
`yyyymmdd`	Convert MATLAB datetime to YYYYMMDD numeric value
`addtodate`	Modify date number by field

Convert to Strings

`char`	Character array
`string`	String array
`datestr`	Convert date and time to string format

Current Date and Time as Numbers or String

`now`	Current date and time as serial date number
`clock`	Current date and time as date vector
`date`	Current date as character vector

Day of Calendar Week or Month

`calendar`	指定日历蒙特h
`eomday`	Last day of month
`weekday`	Day of week

Elapsed Time as Number

etime Time elapsed between date vectors

Topics

Represent Dates and Times in MATLAB

Usedatetimearrays to store date and time information. These arrays support arithmetic, sorting, comparisons, plotting, and formatted display.

Compare Dates and Time

You can perform an element-by-element comparison of values in twodatetimearrays or twodurationarrays using relational operators, such as>and<.

Date and Time Arithmetic
Plot Dates and Durations

Set Date and Time Display Format

TheFormatproperty ondatetime,duration, andcalendarDurationarrays controls the display of values in each array. You can change the value of this property. Changing theFormatproperty does not change the values in the array, only their display.

Specify Time Zones

When you create a datetime, it is unzoned by default. If you work with datetime values from multiple time zones or need to account for daylight saving time, you might need to specify a time zone.

Convert Date and Time to Julian Date or POSIX Time

跨区域共享代码和数据

Follow these best practices when sharing code that handles dates and time with MATLAB^®users in other locales. Write and read dates from other locals.

Core Functions Supporting Date and Time Arrays

Many functions in MATLAB operate on date and time arrays in much the same way that they operate on other arrays.

Troubleshooting

Carryover in Date Vectors and Strings

If an element falls outside the conventional range, MATLAB adjusts both that date vector element and the previous element.

Converting Date Vector Returns Unexpected Output

Because a date vector is a 1-by-6 vector of numbers,datestrmight interpret your input date vectors as vectors of serial date numbers, or vice versa, and return unexpected output.